Double oscillating engine



(No Model.)

B. L. STEVENS.

DOUBLE OSCILLATING ENGINE.

Patented 0015.. 18

INVENTOR: MWM

ATTORNEYS.

UNITED STATES PATENT OFFICE.

ROBERT L. STEVENS, OF ALBANY, OREGON.

DOUBLE OSCILLATING ENGINE.

SPECIFICATION forming part of Letters Patent No. 248,524, dated October 18, 1881,

Application filed May 25, 1881. (No model.)

To all whom it may concern Be it known that I, ROBERT L. STEVENS, of Albany, in the county of Linn and State of Oregon, have invented a new Improvement in Double Oscillating Engines, of which the following is a full, clear, and exact description.

My improvements relate to engines having (two cylinders with pistons connected to a single shaft, and have the object to overcome dead-centers and obtain economical application of the steam or air pressure and expansion.-

The invention combines sector-shaped cylinders, vibrating pistons, and crank-arms, with a slide and connections to the crank-arms, wherebyarule-joint or toggle action is obtained and continuous power applied to the main shaft, as hereinafter described and claimed.

In the accompanying drawings, Figure l is a sectional side elevation of an engine embodying my invention. Fig. 2 is a plan view of the same, and Fig. 3 is a side elevation, showing cylinders of modified form.

Similar letters of reference indicate corresponding parts.

A A are two separate cylinders placed side by side. These cylinders are sector-shaped, and are each fitted with a rock-shaft, a, from which a piston-arm, 1), projects to the curved outer side of the cylinder. The shaft of each cylinder projects at the side and carries a crank-arm, c.

B B are slides fitted in slideways d d on a line with the centers of the shaft or. e e are rods connecting the slides B with the crankarms 0 O is the shaft to be driven, carrying a balance-wheel, J, and also having two cranks or crank-disks, from which rods 9 9 pass to the slides B. The connections of rods 9 to the cranks are at opposite sides of the shaft.

-At h, in the side of each cylinder A, is a steam-port. The exhaust may be arranged in any suitable manner, either through the pistons b, as shown at i, or otherwise.

Suitable valves fitted for operation by connections from the shaft (J will be provided. I do not limit myself to any special form of valve or valve-operating mechanism.

Steam being admitted behind the pistons, theyare moved forward, and the connections from shafts a move the slides B and shaft 0. It will be seen that the arm 0 of each shaft to and its connecting-rod e work as toggle-bars. The greatest angle occurs when the piston is in the backward position. The arm and rod are in line, or nearly so. The power required to move the piston, therefore, diminishes as the piston moves forward, so that the expansive force is utilized to the greatest extent. The pistons are moved forward alternately by admission of steam, so that each effects the halfrevolution of the driven shaft. stroke of each is made by momentum and atmospheric pressure. When steam is used at a pressure below atmospheric pressure the return stroke will be aided by the vacuum formed behind the cylinder; when there steam is exhausted into a condenser.

In Fig. 3 the cylinders D D, instead of being sector-shaped and placed side by side, are

The returnofcircular form in cross-section, and are placed end to end in the arc of a circle concentric with the rock-shafts a, which have double crank-arms, connecting, respectively, with piston-rods 0 and rods 0 to the slides. The operation in this case is the same with respect to the change of angle between the crank-arms and rods, and it is to be understood that the relation of the parts-that is, the angle-may be greatest at the end of the stroke, thus reversing the usual method of using steam by expansion and giving the greatest power at the end of the stroke.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The combination of two sector-shaped cylinders, A, rock-shafts a a, provided with piston and crank-arnis I) 0, slides B, crankshaft O, and connecting-rods c g, substantially as shown and described, for operation as set forth.

2. The combination of two vibrating pistons, separate rock-shafts connected with the pistons, separate slides connected by rods to crank-arms of the shafts, and a double-crank shaft connected to the slides, substantially as shown and described.

ROBERT LIVINGS'IOh STEVENS. lVitnesses:

R. S. STRAHAN, L. BILYEN. 

